U.S. patent number 5,284,445 [Application Number 08/000,670] was granted by the patent office on 1994-02-08 for portable drawing surface with interchangeable components.
This patent grant is currently assigned to Binney & Smith Inc.. Invention is credited to Charles W. Dietterich, Richard A. Tarozzi.
United States Patent |
5,284,445 |
Dietterich , et al. |
February 8, 1994 |
**Please see images for:
( Certificate of Correction ) ** |
Portable drawing surface with interchangeable components
Abstract
This invention relates generally to portable drawing surfaces
and more particularly to a base structure with interchangeable
components. The invention permits the manufacture of a base
structure that can be combined with an accessory unit and a working
surface to create either a lighted drawing surface or a drawing
surface with a utensil accessory tray. This results in substantial
savings in manufacturing costs as tooling requirements are
substantially lowered. The lighted drawing surface includes a
working surface, a lighting accessory unit and a base structure to
provide a backlit surface for tracing and drawing. The portable
drawing surface replaces the lighting accessory unit with a utensil
accessory unit and thereby provides a drawing surface with a tray
for displaying and organizing utensils.
Inventors: |
Dietterich; Charles W.
(Brodheadsville, PA), Tarozzi; Richard A. (Gales Ferry,
CT) |
Assignee: |
Binney & Smith Inc.
(Easton, PA)
|
Family
ID: |
26667964 |
Appl.
No.: |
08/000,670 |
Filed: |
January 5, 1993 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
948811 |
Sep 17, 1992 |
|
|
|
|
Current U.S.
Class: |
434/419; 434/408;
434/413; 434/415; 434/85 |
Current CPC
Class: |
B43L
1/00 (20130101) |
Current International
Class: |
B43L
1/00 (20060101); B43L 001/00 () |
Field of
Search: |
;434/85,88,192,408,409,413,414,415,418,419,432 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Gift and Tableware Reporter, Sep. 7,1 964, p. 25 see "Clip Caddy"
with drawer, lower left. .
Color photocopy of photograph of Binney & Smith Inc., Coloring
Tote. .
Binney & Smith Inc., color photocopy from Crayola Consumer
Products catalogue of Crayola Draw-N-Do Desk. .
Rose Art Industries, Inc., Directions for "Teenage Mutant Ninja
Turtles Light Art". .
Five photographs of Rose Art Industries, Inc., "Teenage Mutant
Ninja Turtles Light Art" toy. .
Binney & Smith Inc. color photocopy from Crayola Consumer
Products catalogue of Crayola Sketch-N-Go..
|
Primary Examiner: Mancene; Gene
Assistant Examiner: Thomas; L.
Attorney, Agent or Firm: Leydig, Voit & Mayer Ltd.
Parent Case Text
RELATED APPLICATIONS
This application is a continuation-in-part of a pending application
of Richard A. Tarozzi, U.S. Ser. No. 07/948,811 filed on Sep. 17,
1992.
Claims
We claim:
1. A portable drawing surface for drawing or tracing
comprising:
a base structure;
an accessory unit removably connected to said base structure;
and
a working surface connected to said base structure or said
accessory unit whereby said working surface is removable by lifting
and pulling away from said base structure or said accessory
unit.
2. The invention as defined in claim 1 wherein said base structure
accommodates different accessory units and different working
surfaces to form portable drawing surfaces with different
characteristics.
3. The invention as defined in claim 1 further comprising:
a hinge to connecting said working surface to said base structure
or said accessory unit.
4. The invention as defined in claim 3 wherein said base structure
includes
a floor having two sections, a front section and a rear section,
said front section being downwardly sloped toward the rear section
and said rear section being relatively flat.
5. The invention as defined in claim 4 wherein said front section
of said floor includes a vertically extending wall for supporting
said working surface.
6. The invention as defined in claim 1 further comprising a
handle.
7. The invention as defined in claim 1 wherein said seat includes
notches for receiving tabbed support structures from said accessory
unit.
8. The invention as defined in claim 3 wherein said hinge is a tab
and slot hinge.
9. The invention as defined in claim 3 wherein said base structure
includes a locking assembly for retaining said working surface to
said base structure.
10. The invention as defined in claim 9 wherein said locking
assembly comprises:
a locking assembly button having tabbed support legs; and
paired slots for receiving said support legs in said base
structure;
wherein said locking assembly button is slidably connected to said
paired slots in said base structure.
11. The invention as defined in claim 10 wherein said base
structure includes recesses on either side of said paired slots for
lifting said working surface.
12. The invention as defined in claim 1 wherein said accessory unit
is a light assembly.
13. The invention as defined in claim 1 wherein said accessory unit
is a utensil tray.
14. The invention as defined in claim 1 wherein said working
surface is translucent.
15. The invention as defined in claim 1 wherein said working
surface includes a trough for holding utensils.
16. A portable lighted drawing surface for drawing or tracing
comprising:
a base structure including a platform;
a working surface connected to said base structure; and
a lighting accessory unit including a light supported by and
removably connected to said lighting accessory unit and said
lighting accessory unit connected to said platform of said base
structure for lighting said working surface.
17. The invention as defined in claim 16 wherein said working
surface is translucent.
18. The invention as defined in claim 16 wherein said working
surface includes a trough for holding utensils.
19. The invention as defined in claim 16 wherein said portable
lighted drawing surface further comprises a hinge to connect said
working surface to said base structure.
20. The invention as defined in claim 19 wherein said hinge is a
tab and slot hinge.
21. The invention as defined in claim 16 wherein said lighting
accessory unit comprises:
a support structure;
a light switch supported by said support structure;
a light bulb supported by said support structure.
a battery compartment including electrical contacts; and
a circuit wherein said light switch, said light bulb and said
contacts of said battery compartment are connected in series.
22. The invention as defined in claim 21 wherein said lighting
accessory unit includes tabbed support arms that mateably connect
with notches in said base structure.
23. The invention as defined in claim 21 wherein said lighting
accessory unit includes an opening that forms said battery
compartment with said base structure forming the bottom of said
battery compartment.
24. The invention as defined in claim 21 wherein said lighting
accessory unit includes a support arm that extends downward thereby
forming a platform for said light bulb.
25. The invention as defined in claim 16 wherein said base
structure includes a sloped floor that reflects light upwards from
said lighting accessory unit and thereby lights said working
surface.
26. The invention as defined in claim 16 wherein said base
structure includes a locking assembly for retaining said working
surface to said base structure.
27. The invention as defined in claim 26 wherein said locking
assembly comprises:
a locking assembly button having tabbed support legs; and
paired slots for receiving said tabbed support legs in said base
structure;
wherein said locking assembly button is slidably connected to said
paired slots in said base structure.
28. The invention as defined in claim 21 wherein said working
surface includes an aperture to accept said light switch.
29. A portable drawing surface for drawing or tracing
comprising:
a base structure;
a utensil accessory tray connected to said base structure for
organizing drawing utensils;
a working surface;
and a tab and slot hinge to connect said working surface to said
accessory tray or said base structure.
30. The invention as defined in claim 29 wherein said base
structure includes a locking assembly for retaining said working
surface fixably connected to said base structure.
31. The invention as defined in claim 30 wherein said locking
assembly comprises:
a locking assembly button having tabbed support legs; and
paired slots for receiving said tabbed support legs in said base
structure;
wherein said locking assembly button is slidably connected to said
paired slots in said base structure.
32. The invention as defined in claim 29 wherein said utensil
accessory tray comprises:
a recess for holding a utensil.
33. The invention as defined in claim 29 wherein said utensil
accessory tray includes tabbed support arms which mateably connect
with notches in said base structure.
34. The invention as defined in claim 29 wherein said working
surface includes a trough for holding utensils.
35. The invention as in claim 29 wherein said working surface is
made of a material so that a magnet adheres to the working
surface.
36. The invention as in claim 1 wherein said working surface is
made of a material so that a magnet adheres to the working
surface.
37. The invention as defined in claim 16 wherein said platform
includes a recess.
38. The invention as defined in claim 16 wherein said platform is
positioned lower than said working surface.
39. The invention as defined in claim 1 wherein said base structure
includes a platform and said accessory unit is connected to said
platform.
40. The invention as defined in claim 29 wherein said base
structure includes a platform and said accessory tray is connected
to said platform.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to portable drawing surfaces and
more particularly to a base structure with interchangeable
components. The invention permits the manufacture of a base
structure that can be combined with an accessory unit and a working
surface to create either a lighted drawing surface or a drawing
surface with a utensil accessory tray. Without this invention, it
would be necessary to manufacture separate base structures to
create drawing surfaces of different characteristics. For example,
one manufacturing line would be needed for molding base structures
for a drawing surface with a utensil accessory tray. An entirely
separate line with another set of manufacturing equipment and
operating personnel would be needed to mold base structures for a
lighted drawing surface. Thus, a great deal of wasteful duplication
in machinery and personnel would be necessary to make two distinct
drawing surfaces.
This invention obviates the need for such duplicative efforts. The
interchangeable nature of the base structure and other components
enables the manufacture of multiple drawing surfaces with
distinctive characteristics from the same base parts. This
invention greatly reduces molding costs since molds for only one
base structure, not two, are needed. This invention results in
substantial savings in manufacturing costs as tooling requirements
are substantially lowered. Thus, this invention permits the
economical manufacture of portable drawing surfaces with either an
accessory tray for storing drawing utensils or a backlit working
surface.
SUMMARY OF THE INVENTION
This invention has evolved with the general object of providing an
improved portable drawing surface at reduced manufacturing
cost.
The present invention provides an improved portable drawing surface
by utilizing a backlit working surface whose lighting chamber
functions additionally as storage for drawing utensils. Thus, the
device provides a lightweight surface that can easily be
transported and used in a variety of settings. The drawing surface
has a dual function as a carrying case which makes the
transportation of any drawing utensils needed for use with the
drawing surface an easy task. Moreover, the invention is provided
with a light bulb and a battery compartment that function to create
a backlit working surface to facilitate tracing of drawings and
patterns. Consequently, the invention provides a flexible, portable
drawing surface that can be taken almost anywhere.
In accordance with an important aspect of this invention, the base
structure of the invention is manufactured to accept
interchangeable accessories. The base structure can accept a
working surface and either: (1) a lighting accessory unit
comprising a battery compartment, a connected light source, and
corresponding circuitry for powering the light source; or (2) a
drawing utensil accessory tray. Thus, the base structure of this
invention can be used to manufacture at least two distinctive
drawing surfaces with correspondingly distinct characteristics
without the need for tooling separate molds for the base structure.
This results in substantial savings in the manufacturing and sale
of portable drawing surfaces as the tooling costs of manufacturing
are greatly reduced. It also reduces manufacturing costs by
obviating the need for separate manufacturing lines for distinct
base structures.
This invention contemplates other objects, features and advantages
which will become more fully apparent from the following detailed
description taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of this invention, reference
should now be had to the embodiments illustrated in greater detail
in the accompanying drawings and described below by way of an
example of the invention.
In the drawings:
FIG. 1 is a left front perspective view of the lighted drawing
surface;
FIG. 2 is a left side elevational view of the invention in FIG. 1
illustrating the handle design and leg supports of the carrying
case;
FIG. 3 is a right side elevational view of the invention in FIG.
1;
FIG. 4 is a top plan view of the invention showing the handle,
working surface and light switch among other features of the
invention;
FIG. 5 is a front elevational view of the invention in FIG. 1
illustrating the latch assembly;
FIG. 6 is a rear elevational view of the invention in FIG. 1;
FIG. 7 is a bottom plan view of the invention;
FIG. 8 is a right front perspective view of the invention with its
working surface in a raised position illustrating the internal
construction;
FIG. 9 is a left front perspective exploded view of the
invention;
FIG. 10 is a dissected cross-sectional view taken along lines
10--10 of FIG. 4 which shows the lighting accessory positioned in
the base structure and the latch assembly;
FIG. 11 is a left front perspective view of the invention assembled
with a working surface and a drawing utensil accessory tray;
FIG. 12 is a partial cross-sectional view taken along lines 12--12
of FIG. 11 showing a utensil accessory tray positioned in the base
structure;
FIG. 13 is a left front perspective view of the invention assembled
with a drawing utensil accessory tray and its working surface in a
raised position; and
FIG. 14 is a left front perspective exploded view of the invention
with a drawing utensil accessory tray.
DESCRIPTION OF A PREFERRED EMBODIMENT
Reference numeral 10 in FIG. 1 refers generally to a lighted
portable drawing surface comprising a base structure 11, a working
surface 12 and a latch assembly 13. The base structure 11 is
constructed from molded plastic. The working surface 12 is also
constructed of molded plastic and is held snugly against the base
structure 11 by the latch assembly 13.
The base structure 11 is molded with various recesses and ridges
that serve various functions. For instance, on the left side of the
working surface 12 in FIG. 1, the base structure 11 is molded to
form a handle 14. The handle 14 slants at a downward angle from the
working surface 12 such that it is narrowest in thickness at the
edge 15 farthest from the working surface. The handle contains a
trapezoidal or D-shaped opening 16. This opening 16 is located near
the back edge 17 of the base structure 11. The opening 16 and the
narrowing angle of the handle 14 combine to create an easily
gripped handpiece 18 for carrying the light box.
As seen in FIG. 1, the base structure 11 also has a utensil trough
19 formed on the right side of the working surface 12. This utensil
trough 19 is rounded such that it resembles a half cylinder. It
runs nearly the entire length of the working surface 12 and is
ideal for holding drawing utensils such as pens, pencils and
crayons.
As seen in FIGS. 4 and 5, the locking assembly 13 comprises a
plastic rectangular button 30 that is positioned in a plane
slightly above but parallel to the working surface 12. The
rectangular button 30 is supported by four support legs 31, 32, 33
and 34. These support legs 31, 32, 33 and 34 can be seen in FIG. 5
and FIG. 10 of the drawings.
Referring again to FIG. 1, the foremost edge 20 of the base
structure 11 provides a functional environment for the locking
assembly 13. As seen in FIG. 5, the foremost edge 20 provides an
upper edge surface 35 that is slightly lower than the working
surface 12 to support the locking assembly 13. This slightly lower
edge surface 35 is connected to the higher edge surfaces 38 and 39
by ramps 36 and 37. Moreover, as best seen in FIG. 7, the base
structure 11 contains two paired grooves 21, 22 that receive the
longest leg supports 31, 33 of the rectangular button 30. These leg
supports 31, 33 have end tabs 40, 41 respectively which slightly
overlap the underside of the base structure 11 and, consequently,
keep rectangular button 30 from inadvertently detaching. Moreover,
as shown in FIGS. 5 and 10, the leg supports 32 and 34 of the
button 30, rest on the top surface of the lower edge surface 35
located between the paired grooves 21, 22. This combination of leg
supports serves to keep the rectangular button 30 positioned in a
parallel plane slightly above the working surface 12.
In operation, the button 30 is slid back and forth in the grooves
21, 22 to either lock the working surface 12 in place or allow it
to be raised as desired. Starting from the locked position, when
the user wants to raise the working surface 12, he would slide the
button 30 forward away from the working surface 12. Support legs 31
and 33 would then slide to their forwardmost position in grooves 21
and 22 respectively. At this point, the working surface 12 will be
able to freely pass upwards without any hindrance from the button
30 of the locking assembly 13. Then, after the working surface 12
is lowered, the working surface 12 can be secured in the closed
position by sliding the button 30 rearward toward the working
surface 12. In its rearward position, button 30 will overlap the
working surface 12 and interfere with its upward movement. As can
be seen in FIG. 4, the button 30 overlaps the working surface 12 in
a snug manner when slid into the lock position and thereby holds
the surface closed during transportation and use.
Referring again to FIG. 1, the base structure 11 can be seen to
have two recesses 50, 51 in the upper surface 35. These recesses
50, 51 form finger holes for lifting the working surface 12 from
the closed position.
As seen in FIGS. 2, 3, 5, 6 and 7, the base structure has four legs
60, 61, 62 and 63. These legs are molded out of the base structure
11. Consequently, they form recesses inside the base structure 11
and corresponding protrusions that act as legs 60, 61, 62 and 63 on
the underside of the base structure as seen in FIG. 7.
As illustrated in FIG. 4, the working surface 12 has several unique
features. The working surface 12 has a semi-cylindrical utensil
trough 70 for holding drawing instruments such as pens, pencils or
crayons. This trough 70 is functionally identical to trough 19
discussed above. The working surface 12 is also constructed with an
oval hole 71 that receives a light switch 72. Thus, the working
surface 12 allows the operation of the lighted drawing surface 10
by providing access to the light switch 72.
As already mentioned, the working surface 12 is held in its locked
position by locking assembly 13. At the opposite end, the working
surface 12 is connected to base structure 11 by means of a tab and
slot hinge. As seen in FIG. 9, base structure 11 is constructed
with two rectangular slots 75, 76 in its back wall. These
rectangular slots 75, 76 receive the tabs 77, 78 of the working
surface to form a hinge-like connection. When the working surface
12 is raised, the tabs 77, 78 swing down in the slots 75, 76. When
the working surface 12 is lowered, the tabs 77, 78 swing back up to
their level position. The interaction between the tabs and the
slots operates like a hinge. While these tabs 77, 78 do not prevent
the removal of the working surface 12, they do provide a semi-fixed
restraint on its movement that allows the working surface 12 to be
lifted without being detached from the base structure 11. This
hinge-like connection can be seen in FIG. 8 of the drawings.
Besides illustrating this hinge-like behavior, FIG. 8 depicts
another important aspect of this invention. In that figure, the
working surface 12 is in a raised position. Thus, the interior of
the base structure 11 is revealed. This interior serves as a
storage area for drawing utensils. It also contains the lighting
accessory unit 80 for illuminating the working surface.
The interior of the base structure 11 consists of a sloping floor
82 and a flat floor 83. The sloping floor 82 runs downward from the
latch assembly 13 to the flat floor 83 and is separated into two
portions by a support wall 85. This wall 85 supports the center of
the working surface 12 during use and thereby prevents breakage or
undue curvature of the surface. The support wall 85 has a notched
section 86 that allows some bending of the working surface 12.
Thus, the notched wall support 85 serves to minimize the stress on
the working surface 12.
The downward sloping floor 82 is positioned at an angle to the
light bulb 90. Consequently, much of the floor's surface is exposed
to the light source. As a result, more light is reflected upwards
due to reflection of the light from the sloped floor 82 than would
be from a flat floor. Thus, the sloping floor 82 results in a more
evenly lit working surface 12.
The internal construction of the lighted carrying case is such that
its heaviest parts, namely, the accessory units, are located at the
back of the structure. As previously mentioned, handle 14 has a
opening 16 that forms a handpiece 18 for easy carrying of the
lighted drawing surface. This opening 16 is located at the rear
section of the handle 14. The handpiece is placed in this rearward
position to accommodate the heavy accessory units that will be
contained at the rear of the body. The carrier's grip will thus be
directly over the heaviest part of the lighted drawing surface.
This will place the grip closer to the lighted drawing surface's
center of gravity than would a more centered grip. Consequently,
this design greatly eases transportation.
In accordance with a further aspect of this invention, FIG. 8
illustrates the placement of the lighting accessory unit 80 in the
base structure 11. The lighting accessory unit 80 comprises a light
bulb 90, the light switch 72 and a support structure 93. The
support structure 93 includes a battery opening 92 which will
accommodate three D cell batteries. As seen in FIG. 9, the base
structure 11, provides a recessed platform 100 with a
semi-cylindrical recess 105 that supports the lighting accessory
unit 80. This recessed platform 100 is constructed with four
notches 101, 102, 103, 104. These notches 101, 102, 103, 104 are
located in the center of each wall of the recessed platform 100.
Thus, they are ideally situated to receive tab supports for the
lighting accessory unit 80.
Referring to the dissected cross-sectional view of FIG. 10, the tab
supports 106, 07 of the accessory unit can be seen penetrating
notches 102 and 103 respectively. These tabbed supports 106, 107
function to retain the lighting unit 80 in place during use and
transportation. FIG. 10 also illustrates the manner in which the
arm support 110 of the support structure 93 carries the light bulb
90. This arm support 110 extends downward to rest on the flat floor
surface 83. Thus, the arm support 110 provides a platform for
presenting the light bulb 90 to the slanting floor 82 and the
working surface 12 for illumination.
Furthermore, as shown in FIG. 10, the trough in the recessed
platform 100 is used to hold batteries 111 to power the light bulb
90. As best seen in FIG. 9, the support structure 93 of the
lighting accessory unit 80 has a rectangular opening 99 in its
center. This opening 99 has downwardly extending contact supports
95, 96 on its short sides. These contact supports 95, 96 serve to
define the ends of the battery opening 92 and to support the
contacts for the battery circuit. As illustrated in FIG. 9, contact
support 96 supports a spring contact 98 that closes one end of the
circuit with the batteries 111. Contact support 95 supports a metal
washer contact 97 that closes the circuit at the opposite end. The
spring contact 98 is compressed when batteries 111 are inserted in
the circuit and holds the batteries in secure contact with one
another and the washer contact 99 to insure a closed circuit at all
times.
As already mentioned, the support structure 93 has a rectangular
opening 99 that forms the outer boundaries of the battery opening
92. Thus, when the lighting accessory unit 80 is placed in the base
structure 11, the semi-cylindrical recess 105 of the recessed
platform 100 completes the battery opening 92. As best seen in FIG.
10, the semi-cylindrical recess 105, includes upward extending
receiving tabs 108 that receive the downward extending contact
supports 95, 96 to retain the contact supports 95, 96 and thus the
contacts 97, 98 in rigid contact with the batteries 111.
Referring to FIGS. 9 and 10, the simple circuit connecting the
batteries 111 to the light switch 72 and the light bulb 90 is old
in the art and need not be explained in detail here. A standard
connecting wire is soldered to the spring contact 98 and to the
light bulb ground connector 114. Another standard connecting wire
is soldered to the power supply contact 115 of the light bulb 90
and to the light switch 72. Finally, a third connecting wire is
soldered between the switch 72 and the washer contact 97 on contact
support 95. Thus, when the batteries 111 are placed between the
spring contact 98 and the washer contact 97 a complete circuit is
formed. Turning the light switch 72 to the "on" position allows
current to flow from the batteries 111 through this simple circuit
to power the light bulb 90. The light from the bulb 90 reflects off
of the sloped floor 82 and the working surface 12 is lit.
In another configuration, the drawing surface would not be lighted.
The working surface 12 is constructed without the oval hole 71 and
can be made of an opaque material. In addition, the lighting
accessory unit 80 can be eliminated. Consequently, the drawing
surface would include a base 11 and a working surface 12. An
accessory unit could be included to prevent materials stored in the
interior of the base structure from entering the semi-cylindrical
recess 105 when the working surface is lowered and the drawing
surface is held in a vertical position. The accessory unit would be
similar to the light accessory unit 80 but would not include the
electrical components. In this configuration, the working surface
12 could be made of a material, such as a paramagnetic material,
e.g. a metal, so that magnets would adhere to the working surface
12.
Another important aspect of the invention is illustrated in FIG.
11. As discussed above, the base structure 11 is made of one piece
of molded plastic and can be made into a lighted drawing surface by
simply adding a lighting accessory unit 80 and a working surface
12. However, the base structure 11 is not restricted to just
receiving the lighting accessory unit, but instead can receive
accessory units with different characteristics. Because of their
different characteristics, these other accessory units can be
combined with the base structure 11 to form many different drawing
surfaces.
FIG. 11 illustrates a drawing surface complete with a utensil
accessory tray 130. The utensil accessory tray 130 includes a
recess 131 and utensil dividers 132. During use, drawing utensils
can be placed standing between the dividers 132 for display. This
display setting makes locating and selecting a desired utensil easy
and temporarily stores the utensils in a neat and organized
fashion.
The utensil accessory tray 130 can be seen in greater detail in
FIG. 14. The accessory tray 130 is positioned on the recessed
platform 100 in a manner analogous to the lighting accessory unit.
Thus, it has a plastic support structure 120 and tabbed support
arms 122, 123 and 124 that function to retain the accessory unit in
place. As best seen in FIG. 12, the tabbed support arm 122 is
received by notch 103 to retain the tray in position during use.
The other two tabs 122 and 124 function in a similar fashion.
However, as illustrated in FIG. 12, the back 125 of the utensil
accessory tray 130 does not have a tabbed support arm but instead
rests directly on the base structure. However, a tab support arm
similar to tab 106 in FIG. 10 may be used with the accessory tray
130. The tray slopes backward as shown in FIG. 9 to better support
drawing utensils between the utensil dividers 132.
FIG. 13 illustrates this embodiment of the invention with its
working surface 136 in the raised position. FIG. 13 also reveals
the internal construction of the invention and the compartment 142
where drawing utensils can be stored during transportation. The
working surface 136 functions with the same sort of tab and slot
hinge as the lighted drawing surface. However, in this embodiment,
the working surfaces tabs are received by slots 138, 140 in the
utensil accessory tray illustrated in FIG. 14. Thus, the working
surface 136 in this embodiment of the invention is smaller than the
working surface of the lighted drawing surface.
In addition, the drawing surface can be constructed with various
characteristics. As already mentioned, the working surface 136
could be made of plastic. However, the working surface 136 could
also be made of a material, such as metal, so that magnets would
adhere to the working surface 136. Alternatively, the working
surface 136 could be made of plastic with metal particles or a
metal layer affixed to a plastic layer to achieve the same magnetic
effect. Also, the working surface 136 could be constructed with a
textured surface or coated with a layer of material so that it
functions as a chalk board.
From the foregoing it will be seen that new and improved drawing
surfaces that can be constructed from the same adaptable underlying
base structure have been brought to the art. This adaptable base
structure allows the low cost manufacture of portable drawing
surfaces of various types and characteristics. It decreases costs
by obviating the need for tooling molds for separate base
structures for each drawing surface type and by obviating the need
for separate manufacturing lines for making separate base
structures. Thus, the invention prevents the wasteful duplication
of machinery and operating personnel for making separate base
structures. Accordingly, the present invention enables the
economical manufacture of portable drawing surfaces of varying
characteristics. In particular, it allows the economical production
of portable drawing surfaces with either a backlit working surface
or an accessory tray for storing drawing utensils.
While particular embodiments of the invention have been shown, it
will be understood, of course, that the invention is not limited
thereto since modifications may be made by those skilled in the
art, particularly in light of the foregoing teachings. It is,
therefore, contemplated by the appended claims to cover any such
modifications as incorporate those features which constitute the
essential features of these improvements within the true spirit and
the scope of the invention.
* * * * *